Published: 03:55 BST, 13 August 2026 | Updated: 03:55 BST, 13 August 2026
Subtle shifts in how you sleep could be an early indicator of your dementia risk, a study suggests.
Everyone has micro awakenings while they sleep, very short periods – usually just a few seconds – when the brain becomes partially awake.
Part of a healthy sleep cycle, people typically experience dozens of these every night and they normally do not remember them.
Now, however, researchers in Europe are warning that having more micro awakenings at night could be a warning sign that someone is at higher risk of cognitive decline.
In a study tracking 500 adults for up to seven years, scientists found that middle-aged adults who had more micro awakenings were more likely to also have genetic markers that raise their risk of Alzheimer's disease.
This included genetic markers such as the APOE4 gene, which is linked to a 60 percent higher risk of an Alzheimer's diagnosis by age 85.
'These micro awakenings are therefore not insignificant,' said co-author Dr Puneet Talwar, a sleep researcher at the University of Liege, Belgium.
'Certain profiles could promote the accumulation of proteins involved in Alzheimer's disease and be associated with increased vulnerability.'
Scientists have revealed a subtle shift in how you sleep that could reveal you are at higher risk of suffering from dementia
About seven million Americans are living with Alzheimer's, estimates suggest, but that number is expected to nearly double over the next 24 years.
Scientists have warned repeatedly that sleep disruption, poor quality sleep and daytime sleepiness may all raise the risk of Alzheimer's disease, possibly because it can cause harmful proteins to build-up in the brain. It was not clear how the genetic markers may disrupt sleep.
The team behind the paper said their research may have revealed a potential method for detecting Alzheimer's risk years before symptoms appear. Typically, the condition is not diagnosed until someone turns 65 years or older.
In the study, published in the journal Sleep, scientists tracked 453 adults with an average age of 22 years and 87 middle-aged adults with an average age of 59 years.
Overall, younger adults slept for about seven hours and 30 minutes per night while middle-aged adults slept for about six hours and 30 minutes per night.